My hub's discovery button isn't working.

As the hub boots up, the lights will rotate and flash. Once the lights are stable and fully lit, you should wait 5-10 more seconds before clicking the discovery button. If the hub lights still do not rotate when pressing the button after the hub has been on for a few minutes then:

Perform a firmware update on the hub. The hub will look for firmware update ten minutes after the hub is completely turned on.